(a) Field of Disclosure
A thin film transistor array panel and a manufacturing method thereof are provided.
(b) Description of Related Technology
In general, a flat panel display such as a liquid crystal display (LCD), or an organic light emitting diode (OLED) display, or an electrophoretic display includes opposed electrodes between which an electric field is generated and one or more electro-optical active layers disposed to be affected by the generated field. The typical LCD includes a liquid crystal layer interposed as the electro-optical active layer between a pixel-electrode and an opposed section of a common electrode. The typical OLED display includes an organic light emitting layer as the electro-optical active layer. Generally one of electric field generating electrodes is referred to as the pixel-electrode and it is generally connected to a switching element (e.g., a transistor) so as to receive an image specifying electrical signal through the switching element. The electro-optical active layer responds to the received electrical signal by forming a corresponding optical signal, thereby displaying a corresponding portion of an image.
Typically, the flat panel display device includes a display panel having a plurality of pixel units arranged in a display area in the form of a matrix, and each pixel unit includes a pixel electrode, a corresponding portion of the common electrode, and a thin film transistor acting as the switching element and connected to the pixel electrode. A gate electrode of the thin film transistor is connected to a corresponding gate line to receive therefrom a row-activating gate signal produced by a gate driver circuit. A source electrode of the thin film transistor is connected to a corresponding data line to receive therefrom a data signal produced by a data driver circuit. The thin film transistor (TFT) operates to selectively couple the received data signal to the pixel electrode of its pixel unit when an activating gate signal is received. Each pixel unit of the display device may output light of one of primary colors such as red, green, and blue, and in some cases additional colors are included such as a white output. An appropriately dyed color filter may be positioned over the pixel unit for outputting the desired spectrum of wavelengths. Alternatively, a color specific emission layer material may be disposed within the pixel unit for emitting the pixel's uniquely colored spectrum of light wavelengths.
In the typical liquid crystal display, the polarity of the applied pixel-electrode voltage, that is the voltage developed between the pixel electrode and the common electrode, is periodically reversed in order to prevent image deterioration due to long-time application of a unidirectional electric field, etc. In other words, the polarities of the supplied data voltages with respect to the common voltage are reversed every frame, or every row, or for every next pixel as examples of such periodic polarity reversals.
The gate driver circuits and the data driver circuits of the display device generally include a plurality of driver ICs. The cost, in particular of the data line driver ICs, tends to be high such that it is desirable to find ways to reduce the number of data driver ICs used in the display device and thus reduce overall cost and complexity. One method of reducing the number of the data driving ICs, is to reduce the number of the data lines provided relative to the number of pixels driven. In one such implementation gate lines and TFTs are clustered close together. This creates a form of asymmetry in the structure because the positions of the thin film transistors are not consistently the same for every pixel. Vertical line blurs may appear due to localized electric field influences between adjacent pixels due to asymmetry and may become perceptible. Artifacts may also develop due to polarity reversal driving (inversion driving).
The above information disclosed in this Background section is only for enhancement of understanding of the related technology and therefore it may contain information that does not form the prior art and is already known to persons of ordinary skill in the pertinent art.